Objective: To evaluate pregnancy rates based on the route of progesterone replacement in frozen embryo transfer (FET) cycles.
Study design: A randomized controlled trial and retrospective analysis. In the randomized group 76 FET cycles were randomized. In the retrospective group 508 FET cycles were reviewed. Intramuscular (IM) proges-erone in oil 100 mg daily or oral micronized progesterone prior to transfer followed by compounded vaginal proges-erone 200 mg 3 times daily (OV). The main outcome measure was the clinical pregnancy rate (CPR).
Results: Baseline characteristics did not vary be-ween groups in either cohort. In the randomized group there were no significant differences in CPR (31.43% vs. 21.05%) or live birth rate (LBR) (31.43% vs. 18.92%) for IM and OV progesterone replacement, respectively. In the retrospective cohort patients there wore also no significant differences in CPR (35.56% vs. 32.35%) or LBR (32.23% vs. 28.51%)f or the IM and OVp rogester-ne replacement groups, respectively.
Conclusion: This study demonstrates that either OV or IM progesterone is effective for luteal phase support for FETs.